Structures that have been, or may have been, exposed to contaminated materials must be inspected and analyzed to determine the extent, if any, of their contamination prior to taking any actions with respect to the structure. For example, remediation of off-gas ventilation stacks requires determining qualitative and quantitative levels of contamination inside each stack in order to determine the plan for demolition and waste disposal.
In many cases, the portions of these structures that have been potentially contaminated are difficult to access. For example, since the purpose of an off-gas stack is to disperse airborne contaminants into the atmosphere at acceptable levels, many of them are hundreds of feet high. Moreover, even if the areas from which samples are to be obtained are physically accessible, placing workers in full personal protective equipment into contaminated stacks of unknown structural integrity to collect the necessary characterization data can be undesirable.